In the field of medical devices, OCR technology is not often used where there is a need for very high accuracy, for example to prevent miss-dosing of a medicament. Thus many mechanical based devices also have dosing scales or readouts which must be manually read and the dose manually recorded. This is time consuming for a user and could potentially lead to errors. Also, if data is to be transmitted electronically and/or analysed electronically, it must first be input manually into a separate electronic device. Furthermore, it may be difficult for some patients (for example those with poor eyesight) to read a mechanical readout, which are often small.
A variety of diseases exists that require regular treatment by injection of a medicament. Such injection can be performed by using injection devices, which are applied either by medical personnel or by patients themselves. As an example, type-1 and type-2 diabetes can be treated by patients themselves by injection of insulin doses, for example once or several times per day. For instance, a pre-filled disposable insulin pen can be used as an injection device. Alternatively, a re-usable pen may be used. A re-usable pen allows replacement of an empty medicament cartridge by a new one. Either pen may come with a set of one-way needles that are replaced before each use. The insulin dose to be injected can then for instance be manually selected at the insulin pen by turning a dosage knob and observing the actual dose from a dose window or display of the insulin pen. The dose is then injected by inserting the needle into a suited skin portion and pressing an injection button of the insulin pen. To be able to monitor insulin injection, for instance to prevent false handling of the insulin pen or to keep track of the doses already applied, it is desirable to measure information related to a condition and/or use of the injection device, such as for instance information on the injected insulin type and dose.